feat(core): add zIndex option to elements

Signed-off-by: braks <78412429+bcakmakoglu@users.noreply.github.com>

packages/core/src/types/edge.ts

@@ -103,6 +103,7 @@ export interface DefaultEdge<Data = ElementData, CustomEvents extends Record<str
   /** contextual and custom events of edge */
   events?: Partial<EdgeEventsHandler<CustomEvents>>
   /** Aria label for edge (a11y) */
+  zIndex?: number
   ariaLabel?: string | null
 }
 
@@ -148,7 +149,6 @@ export interface EdgePositions {
 /** Internal edge type */
 export type GraphEdge<Data = ElementData, CustomEvents extends Record<string, CustomEvent> = any> = Edge<Data, CustomEvents> & {
   selected?: boolean
-  z?: number
   sourceNode: GraphNode
   targetNode: GraphNode
   data: Data

packages/core/src/types/node.ts

@@ -85,6 +85,7 @@ export interface Node<Data = ElementData, CustomEvents extends Record<string, Cu
   /** contextual and custom events that are passed to your custom components */
   events?: Partial<NodeEventsHandler<CustomEvents>>
 
+  zIndex?: number
   ariaLabel?: string
 }